Car Talk

Why is my Check Engine Light Flashing and my Vehicle Shaking?

Avatar Adie Tinkle -

If your vehicle shakes while driving and the engine check light is on, it indicates a problem with the engine. What could be the possible causes of this problem, and how can you fix it? 

Generally, a blinking engine light and shaking of the car indicate a problem with engine components.  

The problem might also be with the fuel supply, engine coil, or a bad spark plug. The car’s shaking, on the other hand, points toward a misfire, as vehicles shake during a misfire. 

However, if the car only shakes when it’s in idle mode, the problem might be with the idle air control valve. It is preferable not to drive your vehicle if the engine light is on or if it’s shaking badly, as this can be a sign of a serious engine fault that you must get checked. 

Possible Causes Behind Check Engine Light Blinking and a Shaking Car

There can be a ton of reasons why your car’s engine check light is blinking. Its purpose is to inform an issue with the engine and its components. However, if your vehicle is shaking along with the check light, there can be various other reasons behind it. 

Let’s explore some of the common causes of a check engine light blinking and a shaking car. 

  1. Blocked Fuel Filter 

A common cause behind a car shaking is an engine misfire, especially when you increase the car’s speed. Possible reasons for this include a lack of adequate fuel pressure in the cylinder. The lack of fuel can also be caused by a blocked fuel filter that has not been changed in a timely manner. If the fuel injector requires a certain amount of fuel that it is not being received, it will cause the cylinder to misfire as the air-to-fuel ratio will be wrong. 

  1. A Defective Fuel Injector 

Faulty fuel injectors can be a common reason of engine problems as they can cause engine shaking and check engine lights to turn on. The role of a fuel injector is to inject fuel into the engine. A bad fuel injector can affect the supply of the engine, which can result in an engine misfire. 

The most common reason fuel injectors fail is that they become blocked or start to leak. A dirty tip or nozzle can also cause blockage. The engine can stay hot for a long time after shutting off because of the heat coming from it. 

Another possible cause of a leaky injector is the failure of the O-ring where the injector connects with the fuel rail. The O-rings are made of rubber that can become brittle and hard due to engine heat. 

  1. The Damaged Ignition Coil

A damaged ignition coil is the common cause behind a check engine light blinking and car shaking.
. Ignition coils are mini transformers that generate a high-voltage current that powers the spark plug. A damaged coil is the common cause of engine light flashing and car shaking. If you try to start the engine with a faulty ignition coil, the engine will misfire, sputter, or might even stall. 

  1. A Faulty Idle Air Control Valve

The air control valve controls the engine’s idle speed by allowing air to pass around the throttle plate with the assistance of a built-in conduit on the throttle body. This is crucial because, during idle engine position, the throttle is completely closed. 

A faulty idle airflow value can cause irregular airflow inside the engine, which can lead to vehicle shaking and engine light blinking. 

  1. Bad Spark Plug 

The role of a spark plug is to provide a spark to ignite the air mixture and fuel inside the vehicle. A fault in the spark plugs can result in a possible cylinder misfire. Also, if the issue is not managed promptly, it can lead to the shaking of the vehicle along with a  flashing check engine light. 

Failure in the spark plug can occur due to the build-up of carbon deposits in the spark plug tip caused by a long-term fuel-to-air ratio imbalance. The spark plug tip can also become burnt, corroded, or even contaminated by engine oil. 

How to Fix a Flashing Check Engine Light and a Shaking Car?

Once you have found out the problem, the next part is to fix the issue. The majority of the issues can be managed by replacing faulty components. However, it is crucial to identify the cause before taking an action.

If you are not aware of the components and functions of the car, it is preferable to hire a professional to have a look. Keep in mind that timely action can assist you in avoiding future deterioration. Therefore, if you encounter any issues, get your vehicle checked in a timely manner. 

By paying attention to the warning light and getting your vehicle checked regularly, you can prevent your vehicle from getting severely damaged and ensure its long running life. 


What do I do if I am dealing with a flashing check engine light and a shaking car?

If you have a flashing check engine light and your car is also shaking, the best option is to stop driving and pull your vehicle to a safe area to prevent future damage to other parts. 

How far can I travel with a shaking car and check engine lights?

If the exact cause behind shaking the car and check light flashing is not defined, there will be no defined time restriction. However, driving the vehicle for long miles with a “check engine light on” can be risky. 

Why is my check engine light flashing?

There can be many causes why your check engine light is flashing, or your vehicle is shaking. If the engine is shaking, there might be a problem with one or more engine components. The issue could also occur because of a faulty ignition coil, bad engine sensors, or spark plugs. To find out the original cause, it is preferable to get the vehicle checked.

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